public class Solution62 {
    public int uniquePaths(int m, int n) {
        /*int[][] dp = new int[m][n];
        dp[0][0] = 1;
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                if (i > 0)
                    dp[i][j] = dp[i - 1][j];
                if (j > 0)
                    dp[i][j] += dp[i][j - 1];
            }
        }
        return dp[m - 1][n - 1];*/
        double res = 1;
        for (int i = m + n - 2; i >= n; i--) {
            res *= i;
        }
        for (int i = m - 1; i > 1; i--) {
            res /= i;
        }
        return (int) Math.round(res);
    }
}
